Punch and die for forming key-opener can-heads



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N. TROYER.

PUNCH AND DIE EOE FURMING KEY OPENER GAN HEADS. No. 535,472. Patented Mar. 12, 1895.

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NELSON TROYER, OF ASTORIA, OREGON.

PUNCH AND DIE FOR FORMING KEY-OPENER CAN-HEADS.

SPECIFICATION forming part of Letters Patent No. 535,472, dated March 12, 1895.

Application {infiamma-2,1894. semina. 527,719. un man.)

To a/ZZ whom it may concern:

Be it known that I, NELSON TROYER, a citizen of the United States, residing in Astoria, in the county of Olatsop and State of Oregon, have invented a new and useful Improvement in Punches and Dies for Forming Key- Opener Can-Heads, of which the following is a specification.

This invention relates to an improved construction of punch and die for the forming of can heads with scored or weakened lines which adapt the can head to be opened by a tearing key.

The nature of the invention will be understood from the following description and claims, and the accompanying drawings, in which- Figure l is a vertical section of the punch and die. Fig. 2 is a fragmentary section of the same on a larger scale showing the punch and die closed together upon the blank. Fig. 3 is a face view of the punch. Fig. 4 is a face view of the die; and Figf is a top view of the punch.

Like letters of reference indicate like parts throughout all the gures.

In said drawings the upper portion of Fig. 1 represents the punch, and the lower portion of said ligure represents the die in section. Referring to the upper portion of said figure, A is the punch stock and A is the movable pad for discharging the can end or head after the same is formed by forcing it out of the punch. The lower outer edge of the stock A is formed with a rabbet to receive two hardened and ground steel rings a and b. These rings fill the rabbet, and the outermost one has its periphery iiush with theperiphery of the punch stock. E is the soft steel cutting ring made internally of a diameter to slip up over the punch stock and provided with an internal ledge p which sits under the hardened steel ring a, leaving only the inner corner of said ring a. exposed. This ledge p supports the ring a and holds it in place, the ring b being held in place either by friction between the punch stock and the ring aorin any suitable manner as by removable dowels or otherwise. The soft steel cutting ring E not only supports thering a, but by embracing the punch stock and rings serves to form a solid case around the rings a and b to withstand any strain put upon them in the operation of punching. The soft steel cutting ring E is held rmly to the die stock by means of the external ring G which has a screw thread cut on its inner surface to engage a screw Athread cut upon the outer surface of the ring E. The upper portion of the ring G sets upon the punch stock and when screwed firmly down holds the parts solidly together. The exposed inner corner of the hardened and ground steel ringe forms a scoring point or edge for forming the outer score on the upper surface of the can head. This scoring edge is marked ct. The under surface of the hardened and ground steel ring b is shaped to conform to the configuration which it is desired to give to the outer margin of the can head, namely a curve. The inner edge of the ring b forms a holding up point or edge h to oppose the force of a scoring edge situated in the die beneath and which will presently be described. It will be noticed that the parts of the punch which are subjected to wear, namely the rings E a and b may be readily removed for grinding or replacement by simply unscrewing the external ring G, and that when in place of all the parts are solidly and firmly held against any strain in operation.

Referring to the lower half of Fig. 1, B is the die stock in which are formed rabbets to receive the hardened steel rings c and d and the soft steel ring e which may be simply dropped or slipped in place. The upper outer portion of the soft steel ring e is provided with a projecting ledge e' setting over the upper end of the hardened steel ring d, leaving only the outer edge of said hardened steel ring d exposed. B is the steel cutting plate between theinner edge of which and the outer edge of the cutting ring E the blank out of which the can head is to be formed is cut in the descent of the punch upon the die. The usual spring blank holder for holding the blank while the punch and die are operating to form the same is of the usual construction and is indicated in the drawings, but need not be specifically described.

The outer upper edge marked c of the ring c is vertically in line with the inner lower edge of the ring a, and the outer upper edge,` marked d of the ring d is in line with the inner lower edge of the ring b. The corner or edge o forms a hold up point to oppose the cutting and indenting action of the scoring edge a in the punch, and the edge d forms a scoring corner or edge in the die which is opposed in the punch by the hold up edge b on the ring b. This arrangement of hold up and scoring edges, an inner corner opposing an outer corner vertically, gives a shearing action which facilitates the scoring and adds greatly to the durability of the apparatus. The arrangement is such that the outer score is made on the upper surface of the can head and the inner score on the under surface of the can head. This arrangement of the inner score on the under surface of the can head is highly important in the manufacture of scored can heads for the reason that when the inner score is on the under surface it does not need to be made so deep to form an easily opened tearing strip as Where this inner score is formed upon the outer or upper surface of the can head. Great difficulty has been experienced in the manufacture of these can heads owing to the liability of the inner score ripping or tearing open under the pressure of the processing of the can if said inner score is made deep enough to permit a ready opening of the can by the use of the key. I I

find that by making the inner score on the under surface of the can head and the outer score on the upper surface of the can head the exact results desired of strength against bursting and ease of opening are attained, and hence this arrangement in the punch and die.

I claim- 1. The combination of the punch stock A, the die stock B, the hardened steel rings a b, the soft steel externally screw threaded cutting ring E, the internally screw threaded fastening ring G, constructed to screw over E. the hardened steel rings c and d in the die stock, the ring e having a projecting ledge e all constructed and arranged substantially as specified.

2. The punch and die provided with indents and opposing hold outs' for forming an inner and an outer concentric weakened line or indentation, and arranged to form the inner indentation only on the underside of the can head, substantially as specified.

E. G. ROGERS, S. S. GORDON. 

